Orgasm, laughter, and tears

Sex, emotional connection, heavy breathing, and the highway to orgasm. Then, somewhere right after it starts, I burst out laughing for no reason at all. Everyone asks me what I'm laughing about, but I've literally never had the correct answer. Sometimes it's the itchy sensation all over my body, but my response often comes spontaneously. The laughter that, for a few moments after orgasm, ...